2001 BMW 740 Smoking upon startup

2001 BMW 740
94,247 MILES • V8 • 2WD • AUTOMATIC
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HEIFETZ17
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I recently replaced my oil separator valve/rear intake cover and gasket, along with the throttle body gasket and intake manifold gaskets. Shortly after, I replaced the valve cover gaskets and upper timing cover gaskets.

Immediately after replacing the valve cover gaskets and timing cover gaskets, I noticed the car started smoking at startup. I just replaced the rear valve, so I know that's not the issue. Some people have told me the oil separator/cyclone (inside the timing cover) is bad.

My question is, what else could be causing this? Could I have knocked a chunk of gunk into a drain tube somewhere causing oil to back up into the intake? This problem wasn't happeneing until I replaced the gaskets, and I didn't even touch the cyclone (especially as it's tucked away behind the timing chain. I highly doubt that by some estonishing coincidence the cyclone failed at the exact time that I replaced these gaskets.

Thanks very much for any assistance!
Dec 22, 2009 at 9:32 PM
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DOCHAGERTY
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The oil seperator is in the front of the left hand cylinder bank and may be the cause, inspect for damage and be prepared to replace the the seperator and possibly some or all of the tensioners/guides for the timing chain.

https://www.2carpros.com/articles/mitchell1eautorepair-car-repair-manuals
Dec 23, 2009 at 10:58 AM
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HEIFETZ17
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Is there any way to test this component? There are no visual signs of damage. There's a drain tube leading from the separator to the oil pan. If this tube were blocked, could this be causing oil to back up into the intake?

Thanks very much for your help!
Dec 23, 2009 at 7:25 PM
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DOCHAGERTY
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Yes, and it probably is blocked.
Dec 23, 2009 at 11:53 PM
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HEIFETZ17
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Great! I'll look into clearing the tube and see if it helps. Thanks very much for your help!
Dec 24, 2009 at 1:03 AM